Discovery of a novel mode of protein kinase inhibition characterized by the mechanism of inhibition of human mesenchymal-epithelial transition factor (c-Met) protein autophosphorylation by ARQ 197

J Biol Chem. 2011 Jun 10;286(23):20666-76. doi: 10.1074/jbc.M110.213801. Epub 2011 Mar 24.

Abstract

A number of human malignancies exhibit sustained stimulation, mutation, or gene amplification of the receptor tyrosine kinase human mesenchymal-epithelial transition factor (c-Met). ARQ 197 is a clinically advanced, selective, orally bioavailable, and well tolerated c-Met inhibitor, currently in Phase 3 clinical testing in non-small cell lung cancer patients. Herein, we describe the molecular and structural basis by which ARQ 197 selectively targets c-Met. Through our analysis we reveal a previously undisclosed, novel inhibitory mechanism that utilizes distinct regulatory elements of the c-Met kinase. The structure of ARQ 197 in complex with the c-Met kinase domain shows that the inhibitor binds a conformation that is distinct from published kinase structures. ARQ 197 inhibits c-Met autophosphorylation and is highly selective for the inactive or unphosphorylated form of c-Met. Through our analysis of the interplay between the regulatory and catalytic residues of c-Met, and by comparison between the autoinhibited canonical conformation of c-Met bound by ARQ 197 to previously described kinase domains of type III receptor tyrosine kinases, we believe this to be the basis of a powerful new in silico approach for the design of similar inhibitors for other protein kinases of therapeutic interest.

MeSH terms

  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / enzymology*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Catalytic Domain
  • Clinical Trials, Phase III as Topic
  • Crystallography, X-Ray
  • Humans
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / enzymology*
  • Lung Neoplasms / genetics
  • Phosphorylation / drug effects
  • Protein Binding
  • Protein Kinase Inhibitors / chemistry*
  • Protein Kinase Inhibitors / therapeutic use
  • Protein Structure, Tertiary
  • Proto-Oncogene Proteins c-met / antagonists & inhibitors*
  • Proto-Oncogene Proteins c-met / chemistry*
  • Proto-Oncogene Proteins c-met / genetics
  • Proto-Oncogene Proteins c-met / metabolism
  • Pyrrolidinones / chemistry*
  • Pyrrolidinones / therapeutic use
  • Quinolines / chemistry*
  • Quinolines / therapeutic use

Substances

  • ARQ 197
  • Protein Kinase Inhibitors
  • Pyrrolidinones
  • Quinolines
  • Proto-Oncogene Proteins c-met

Associated data

  • PDB/3RHK